PATH 372 Diseases of Horticultural Crops

3) Choanephora blight /Wet Rot (Choanephora cucurbitarum)
Symptoms:
The pathogen attacks flowers, buds and tender young shoots.
This disease produces a blossom blight as well as a fruit rot stage and occasionally
a leaf blight.
Blossoms exhibit a lack of turgidity as petals begin to wilt.
Luxuriant growth of the pathogen is seen on infected portion which appears as
black pin heads or Stiff whisker-like strands of the causal fungus, topped with
black heads (sporangia) grow off the infected blossoms causing a blossom drop.
Young fruit may become infected, soften and abort with the black fungal growth
apparent on the fruit.
Management:
A dopt recommended spacing to maintain adequate air circulation.
Select the seeds from healthy fruits and treat the seed with captan or
thiram@3g/kg seed
Spray Mancozeb@0.25% or Copper oxy chloride@0.3%
Grow resistant varieties like Seoul hot, Liachi-2, AT-Good, etc.
4) Mosaic complex
Chilli mosaic virus, Potato Virus Y, Cucumber Mosaic Virus (CMV), Tobacco
Mosaic Virus (TMV) and Tomato spotted wilt virus
Symptoms: Symptoms vary with the infected virus
TMV:
• Backward bending of petiole
• Raised blisters and mottled areas of light and dark green areas on the foliage
• Leaves point towards ground.
• Necrotic spots on stem.
• Fruit ripens unevenly and is reduced in size
CMV
• Downward curling along with midrib
• Most plants exhibit some degree of "shoestringing" (narrowing of the leaves) in
addition to stunting, yellowing, and whitish spotting of the leaves.
• Fruit may be small and distorted.
PVY
• Vein banding
• Small, crinkled leaves.
Spread
Sap transmissible (TMV)
Aphids: Myzus persicae, Aphis gossypii, A. craccivora
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